Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/0006—Controlling or regulating processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
  • B01F23/45—Mixing liquids with liquids; Emulsifying using flow mixing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/50—Circulation mixers, e.g. wherein at least part of the mixture is discharged from and reintroduced into a receptacle
  • B01F25/53—Circulation mixers, e.g. wherein at least part of the mixture is discharged from and reintroduced into a receptacle in which the mixture is discharged from and reintroduced into a receptacle through a recirculation tube, into which an additional component is introduced
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/80—Mixing plants; Combinations of mixers
  • B01F33/836—Mixing plants; Combinations of mixers combining mixing with other treatments
  • B01F33/8361—Mixing plants; Combinations of mixers combining mixing with other treatments with disintegrating
  • B01F33/83614—Mixing plants; Combinations of mixers combining mixing with other treatments with disintegrating with irradiating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/80—Mixing plants; Combinations of mixers
  • B01F33/836—Mixing plants; Combinations of mixers combining mixing with other treatments
  • B01F33/8362—Mixing plants; Combinations of mixers combining mixing with other treatments with chemical reactions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/18—Stationary reactors having moving elements inside
  • B01J19/1868—Stationary reactors having moving elements inside resulting in a loop-type movement
  • B01J19/1881—Stationary reactors having moving elements inside resulting in a loop-type movement externally, i.e. the mixture leaving the vessel and subsequently re-entering it
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/28—Moving reactors, e.g. rotary drums
  • B01J19/285—Shaking or vibrating reactors; reactions under the influence of low-frequency vibrations or pulsations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F2025/91—Direction of flow or arrangement of feed and discharge openings
  • B01F2025/914—Tangential flow, i.e. flow spiraling in a tangential direction in a flat plane or belt-like area
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/05—Stirrers
  • B01F27/07—Stirrers characterised by their mounting on the shaft
  • B01F27/072—Stirrers characterised by their mounting on the shaft characterised by the disposition of the stirrers with respect to the rotating axis
  • B01F27/0725—Stirrers characterised by their mounting on the shaft characterised by the disposition of the stirrers with respect to the rotating axis on the free end of the rotating axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/05—Stirrers
  • B01F27/11—Stirrers characterised by the configuration of the stirrers
  • B01F27/112—Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F31/00—Mixers with shaking, oscillating, or vibrating mechanisms
  • B01F31/80—Mixing by means of high-frequency vibrations above one kHz, e.g. ultrasonic vibrations

Definitions

• the invention relates to a method for treating substance or mixture of substances located in a container, in particular by mixing or stirring processes rotating around the container axis.
• mixing is a substance distribution process in which two or more substances are brought into a state of as complete a uniform distribution as possible, by means of circulation processes of the substance components to be mixed.
• mixing processes take place in many branches of industry, in which other solid, liquid or gaseous components are to be distributed evenly in large quantities of liquid. Such processes take place in agitators, reactors, crystallizers, wastewater tanks, flue gas scrubbers, fermenters and many other devices.
• the invention has for its object to provide a method for treating substance or mixture of substances located in a container, in particular by mixing or stirring processes, in rotation about the axis of the container, which enables gentle treatment of the fluid substance or the mixture, through which the required energy input can be reduced without adverse effects on the mixing quality and with which the problems of heat transfer can be solved satisfactorily without great expenditure on equipment. It is also an object to provide a device which is suitable for carrying out the method.
• the object is achieved by the procedure specified in claim 1. Suitable embodiments of the method are specified in claims 2 to 21. A device suitable for carrying out the method is the subject of claim 22. Suitable design variants for the device are specified in claims 23 to 32.
• the solution according to the invention is based on the considerations of using the tangential speed component of the material to be mixed, in particular during the mixing and stirring process, in order to discharge the material from the container in the circuit and to return it to the container at another point.
• a partial flow of the mixed material or a mixed material component can thereby be partially or completely removed from the circuit and subjected to a special treatment during the circulation.
• the cycle in the sense of the invention is to be understood as the distance of the mixed material outside the container.
• the simplest embodiment of a device for carrying out the method according to the invention is the arrangement of a line leading tangentially from the container wall to the outside, which line acts as an outer circulation line up to the desired one Place of the container is guided.
• the line is arranged in the container wall in such a way that the central axis of the line has the same direction as the tangential speed component of the mixture rotating in the container or a direction slightly inclined to it.
• the deviation in the angle of inclination from the 5 central axis can be up to 45 °. This means that practically the entire dynamic pressure difference becomes the driving force for an external material cycle.
• the difference in height of the inlet and outlet openings in the container is not important, since only the pressure losses due to the flow movement have to be applied as energy.
• the tangential speed is not a function of the container height in a first approximation, since a rigid body vortex is practically formed, which decays from a certain radius coordinate to the container wall.
• the mixture inside the container can be influenced by two mechanisms.
• the usual mixing action is provided by the mixing or stirring element.
• the jet mixture is added by the fluid jet which is circulated and introduced into the container. For the introduction there is only the condition that the direction of flow is not the tangential speed.
• 35 speed component may be directed in opposite directions. For example, it can be aligned radially to the axis of the container and can also deviate from the horizontal. This opens up a multitude of possibilities for practice.
• the circulation quantity does not always have to be guided from bottom to top.
• the material is grasped on the surface of the liquid and carried down through the line.
• the gas can be added in the upper part of the line, after which it is drawn down by the liquid.
• the gas is in contact with the liquid more intensively and longer than if it is only introduced at the bottom, which also entails higher energy costs, since it has to be compressed to a higher pressure. It can also make sense to combine both directions by operating the delivery direction from top to bottom for gas entry and the opposite direction in parallel for the suspension. Additional heat and mass transfer processes, for example, can take place in the circuit between the discharge point and the feed parts. The necessary installations, which are known per se in their structural design, are then carried out in the circuit line.
• the ultrasound influencing of a liquid in the circulating stream can be initiated.
• the measurement of material and operating parameters is also possible.
• the tank can be equipped with several tangential nozzles and the associated circuit lines. This makes it possible to selectively switch on or off several circuits. This means, for example, that dirty heat exchangers can be taken out of operation for cleaning while the other circuit remains in operation. In the case of dirty coils inside a stirred tank, the process would have to be stopped.
• Several circuits can also be used to react to different process requirements, such as different fill levels or changing material values.
• the solution according to the invention is suitable for a large number of tasks, in particular in the field of chemical process engineering, such as, for example, supplying heat or introducing heat (for crystallization processes or chemical reactions), feeding gas (removing from the top, feeding below), suspending (removing below, feeding) above), admixing other substances, measuring material or process engineering parameters, taking a partial flow, classifying a withdrawn partial flow and homogenization of substances in large and tall containers.
• chemical process engineering such as, for example, supplying heat or introducing heat (for crystallization processes or chemical reactions), feeding gas (removing from the top, feeding below), suspending (removing below, feeding) above), admixing other substances, measuring material or process engineering parameters, taking a partial flow, classifying a withdrawn partial flow and homogenization of substances in large and tall containers.
• the required rotational movement of the substance in the container can be generated by the rotating stirring or mixing elements, such as e.g. is the case with batch processes.
• the rotational movement of the substance in the container can also be generated by the additional introduction of a fluid substance.
• a gas or a liquid evaporating during the process are introduced, which cause a sufficient rotational movement of the substance in the container.
• at least one defined material flow should be continuously discharged again, according to the inlet and outlet principle.
• the desired rotational movement is preferably achieved by a tangential introduction of the liquid flow. In this case, the entry energy of the liquid must be the friction loss of the
• Limit values are regulated.
• the lowest energy pulse is achieved when all the supply channels are acted on with the total entry quantity.
• the greatest input pulse is achieved when the smallest cross-section is applied to the feed channel.
• the liquid can be removed or discharged in the area of the container rim. If the liquid remains in the container for a long time, the energy of the quantity of liquid supplied will usually not be sufficient to replace the frictional energy. Then an additional amount can also be pumped in a conventional manner.
• This circulation amount is then to be added to the amount of liquid which is fed to the stage in order to form the total amount of liquid in the sense of the regulation described.
• the effectiveness of the separate supply of a fluid material flow to generate the required rotational movement of the material in the container does not differ from the use of stirring or mixing elements.
• these two alternative measures can also be used in combination, for example in those applications where only gentle stirring movements are desired which are not sufficient to ensure the required rotational movement of the material to be mixed.
• the process is suitable for fluid substances or mixtures of substances with solid or fluid substances.
• the process is less suitable for substances or mixtures of substances that consist exclusively of solid substances of large grain sizes or have a high viscosity.
• the proposed solution enables a gentler treatment of the respective substances, leads to a better mixing effect and thus to a higher mixing quality.
• the mixing times can be shortened for certain processes without having an adverse effect on the mixing quality.
• the required mass transport outside the container, that is to say in the circuit does not require any additional energy input. As a result, the energy balance for various mixing and stirring processes can be made significantly cheaper and leads to a reduction in costs.
• Fig. 2 shows the stirred tank of FIG. 1 as a half section, in one around the central
• FIG. 3 the top view of the stirred tank according to FIG. 2
• FIG. 4 the schematic illustration of a stirred tank for a circular operation from top to bottom
• FIG. 5 shows the schematic representation of a stirred tank with a heat exchanger integrated in the circuit for an evaporation crystallization
• FIG. 6 shows a functional diagram for a further embodiment variant with several circuit leads.
• a pipe section 6 is tangentially integrated, for example by welding or gluing.
• the pipe section 6 is arranged in the curved area of the lateral surface 3 in order to bring about an additional rinsing effect in the floor area in the operating state.
• the tangentially arranged pipe section 6 can of course, depending on the process conditions, be arranged at a different location on the lateral surface 3.
• the pipe section 6 leading outward is integrated in such a way that its central axis M has the same direction as the tangential speed component of the material to be stirred which is produced in the operating state.
• an arcuate pipe section 7 is flanged to which an interchangeable
• Intermediate piece 8 is connected, which is connected to a second arcuate tubular piece 9, to which a further tubular piece 10 is flanged, which is integrated into the container wall 3 at another location on the lateral surface.
• the circuit line 13 extends from the outlet opening or discharge point 11 (FIG. 3) to the higher entry opening or return point 12 (FIG. 2) only over a partial area of the lateral surface 3 of the container 1
• the return point 12 must be aligned so that the material flow is not directed in the opposite direction to the tangential velocity component in the stirred tank.
• the intermediate piece 8 can be replaced by a corresponding component with additional functions, e.g.
• the intermediate piece 8 can also be designed as a T-piece if it is necessary to enter a further component, in which case the arrangement of a static mixer can be expedient.
• the closed stirred tank 1a shown in FIG. 4 is intended, for example, for such an application when lighter particles are to be mixed into a liquid.
• the built-in tangential pipe socket 6a which forms the discharge point for the portion to be removed, is located below the liquid level H.
• the particles are discharged with the flow through the pipe socket 6a due to the tangential velocity component of the liquid in the stirred tank 1a and reach the lower pipe socket 10a, which is arranged radially to the central axis of the container, via the circuit line 13a (not shown) in the direction of the arrow shown.
• the circuit line 13a is dimensioned such that the rate of rise of the particles is less than the average flow rate in the line 13a.
• FIG. 5 shows a stirred tank in which a heat exchanger 14 for evaporative crystallization is integrated in the circuit line 13b.
• a concentrated mother liquor is evaporated.
• the solvent is removed by evaporation and crystals are formed.
• the aim of the process is to extract the largest possible crystals. It is therefore necessary to treat the crystal produced with care.
• the circulation is carried out in the same way as in the variant shown in FIGS. 1 to 3 from bottom to top.
• the mother liquor is set into a primarily tangential movement by a blade stirrer, not shown, and reaches the heat exchanger 14 via the outlet opening 11 of the tangentially arranged pipe socket 6b, which is integrated near the bottom in the tank wall 3, and via an intermediate piece, not shown the temperature of the mother liquor is increased by a few degrees.
• a supply line 15, which is marked as an arrow, is integrated, via which fresh mother liquor is introduced into the circuit, by means of a separate pump.
• a further line 17 is integrated into the line 16 connected to the tangential nozzle 6b, via which a partial amount of mother liquor is removed and fed to a centrifuge. It is advantageous that no pump is required for the circulation of this subset, since the transport to the centrifuge takes place via the existing dynamic pressure difference between the two connection points in the container, the discharge and return point. The material cycle via the heat exchanger also takes place exclusively as a result of the existing dynamic pressure difference.
• the solution according to the invention leads to a particularly gentle treatment of the crystals, especially in this process.
• the rotational movement of the container goods is essentially maintained by the circulation flow.
• the speed of the stirrer can thus be considerably reduced, which on the one hand prevents undesirable abrasion of the crystals and on the other hand enables an energy-saving mode of operation.
• FIG. 6 a functional circuit diagram is shown in a simplified form of an embodiment variant in which a plurality of partial streams are removed from the stirred tank 1 via separate circuit lines 13 and 13 'and returned to the tank without additional energy input.
• the material cycles take place exclusively as a result of the existing dynamic pressure difference.
• Via the two circuit lines 13 and 13 ' two separate amounts of partial electricity are discharged from the container 1 near the bottom and returned to the upper part of the container.
• the tangential lines or connections leading outwards are not arranged in their central axis identically with the direction of the tangential speed component, but in a position inclined by the angle ⁇ .
• the simplest area of application is the mixing of fluids with other solid or gaseous phases. Even if there are no heat and mass transfer processes, this procedure has its advantages. In the first place, attention should be drawn to the saving of energy.
• the liquid can be led through the outer line up to the upper layer of the container. There is no mixing with the surrounding fluid and therefore braking as with the flow in the container.
• the amount to be conveyed upwards can be determined according to the sinking speed of the particles in the suspension.
• cross-mixing can also be achieved through the freely selectable position of the feed into the apparatus.
• the process has a particularly favorable effect on large and tall containers. Possible applications are e.g. in flue gas cleaning. A lime suspension must be stirred in the swamp so that differences in concentration can even out. A considerable amount of energy is currently used for the mixture because the containers are very large and tall.
• Reactors also bioreactors
• Suspended particles are often contained in multiphase reactors. These particles often have to be treated carefully. It can be living organisms in bioreactors or catalyst particles in chemical reactors. Abrasion is considered harmful because the service life and effectiveness of the catalyst are impaired. Nevertheless, thorough mixing should take place in the reactor, which can take on considerable dimensions, for example in the case of bioreactors (fermenters).
• the low shear effect of blade stirrers compared to propeller stirrers is known. The blade stirrers effectively cause one Rotational flow that can be used for the axial transport of the liquid. The method according to the invention therefore enables the possibility of mechanically gentle circulation.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Mixers With Rotating Receptacles And Mixers With Vibration Mechanisms (AREA)
• Processing Of Solid Wastes (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7906513

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (6)

Family Cites Families (16)

• 1999
  • 1999-04-30 DE DE19919859A patent/DE19919859C2/de not_active Expired - Fee Related
• 2000
  • 2000-04-28 WO PCT/EP2000/003876 patent/WO2000066255A1/fr active IP Right Grant
  • 2000-04-28 DE DE50001715T patent/DE50001715D1/de not_active Expired - Fee Related
  • 2000-04-28 AT AT00934973T patent/ATE236711T1/de not_active IP Right Cessation
  • 2000-04-28 AU AU50634/00A patent/AU5063400A/en not_active Abandoned
  • 2000-04-28 EP EP00934973A patent/EP1175255B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events